I did the compatibility tester app thing and it was inconclusive. I looked at the wires and it told me to take pictures and attach it to this forum (below) for confirmation of compatibility. I'm hoping my heating system is compatible with nest but I'm just not sure. Please help on this issue, thanks so much!
Thanks for reaching out. Google Nest thermostats are designed to work with most 24 V systems, even older systems. They work with all common fuel types including natural gas, oil, and electricity. You can also click on this link to learn more about systems that are compatible with the Nest Thermostat.